Answer:
Heart rate=80 beats per minute
Uncertainty=3 beats per minute
Explanation:
We are given that a person measures heart beat by counting the number of beats in 30 s.
If number of beats=
Time=
We have to find the heart rate and its uncertainty in beats per minute
Maximum number of beats=40+1=41
Minimum time=30.0-0.5=29.5 s
Because when heart beat increases then time reduces.
We know that 1 minute =60 seconds
Therefore, time =
Average number of beats=40
Average time=30 seconds=
Heart rate =
Heart rate =
Maximum heart rate=
When minimum number of beats=40-1=39
Maximum time=30.0+0.5=30.5 seconds
Because when heart beat slow then it takes more times
Time=
Minimum heart rate=
Uncertainty when heart rate is maximum
Uncertainty=83.33-80=3.33 beats per minute
Uncertainty when heart rate is minimum
Uncertainty=80-76.77=3.23 beats per minute
Average uncertainty=
Average uncertainty=3.28
beats per minute
Hence, heart rate=80 beats per minute
Uncertainty=3 beats per minute